HABEAS CORPUS; LACK OF NOTICE; NON-APPEARANCE EQUIVALENT TO WAIVER TO BE PRESENT AT PRELIMINARY INVESTIGATION. Petitioner's failure to appear at the preliminary investigation was due to the fact that he did not receive any notification either from the Court or from his bondsmen about said preliminary investigation. Petitioner's non-appearance was involuntary, due to his lack of knowledge of the preliminary investigation to be held. Held: Even if he was duly notified, his failure to appear, at most, can be considered as a waiver, of his right, according to the Rules, to be present at said preliminary investigation.